That's a great question! Enzymes are amazing molecules that can speed up chemical reactions without being used up themselves. Here's the breakdown of what happens to their shape:

* Enzymes are highly specific: Each enzyme has a unique active site that fits only a specific type of molecule called a substrate.

* Induced fit: When the substrate binds to the active site, it causes a slight change in the enzyme's shape. This is called "induced fit," and it's like a handshake where both hands adjust to fit perfectly.

* The reaction occurs: This shape change helps the enzyme to position the substrate in a way that makes the reaction more likely to occur.

* The product is released: Once the reaction is complete, the product is released from the active site, and the enzyme reverts to its original shape.

So, the answer is yes and no:

* Yes: The enzyme changes shape slightly when the substrate binds.

* No: After the product is released, the enzyme returns to its original shape.

Think of it like this: The enzyme is like a lock, and the substrate is like a key. The key fits into the lock (induced fit), and the lock changes shape slightly to hold the key (the reaction occurs). Once the key is released (the product is released), the lock returns to its original shape.

Let me know if you have any other questions about enzymes!